[Clinical characteristics of patients with acute renal infarction: an analysis of 52 patients in a single center].

OBJECTIVE: To investigate the clinical characteristics of patients with acute renal infarction (ARI) and explore the possible clinical and/or laboratory parameters relative to hematuria.
METHODS: Medical records of 52 patients hospitalized with radiologic proven ARI were retrospectively reviewed. Clinical characteristics, including demographic data, risk factors for thromboembolism, initial clinical presentations, laboratory data, diagnosis, treatment programs and outcomes were evaluated and compared between hematuria(+) and hematuria(-) patients.
RESULTS: The mean age of the patients (34 men and 18 women) was (56.3±14.8) years. The left, right, and bilateral kidneys were involved in 44.2%, 34.6% and 21.2% of the patients, respectively. Focal, multiple and massive infarctions were involved in 36.5%, 50.0% and 13.5% of the patients. The prevalence of concurrent thromboembolic events was 38.5%. Atrial fibrillation was complicated in 44.2% of the patients. ARI often presented with nonspecific symptoms, including abdominal/flank pain (71.2%), nausea (55.8%), lumbar pain (53.9%), vomiting (48.1%), fever (48.1%), and diarrhea (21.2%). Percussion tenderness over kidney region was the most common sign (40.4%). The levels of serum lactate dehydrogenase, white blood cell count and C-reactive protein were elevated in 86.5%, 67.3%, and 54.5% of cases, respectively. Hematuria was detected in only 38.5% of the cases on admission. Elevation of serum D-dimer was only noted in 56.5% of the patients. The median duration from hospital presentation to diagnosis was 41.5 h (range: 2-552 h). Contrast-enhanced computed tomography was diagnostic in 47 (90.4%) cases. Angiography was positive in the other 5 (9.6%) cases. Anticoagulation was the most common therapy. During a mean follow-up of (39.4±35.8) months, renal functions of most patients were stable. Four patients needed permanent dialysis and one patient died of heart failure. There was no statistical significance between hematuria (+) group and hematuria (-) group for all the parameters except the level of serum lactate dehydrogenase, which was higher in hematuria(+) group [773.5 IU/L (range: 153.0-3 159.0 IU/L) vs. 488.0 IU/L (range: 137.0-3 370.0 IU/L), P=0.041].
CONCLUSION: Thromboembolism due to heart disease is the main etiology of ARI. Early contrastenhanced computed tomography scan should be considered for high-risk patients with persisting abdominal or lumbar pain and elevated serum level of lactate dehydrogenase. Hematuria is not a sensitive clue for diagnosis and is not relative to prognosis. Whether it is present may be determined by the severity of infarction.